User manual HARBACH ELECTRONICS PS-220

[. . . ] PS-220 PARASITIC SUPPRESSOR KIT INSTALLATION INSTRUCTIONS PART S SUPPLIED WITH T HIS KIT : (2) (1) (2) (2) Plate/Resistor Choke Assemblies Tuning Capacitor Feed Suppressor 10 2W Metal Film Resistors 0. 01µF 1KV Ceramic Disc Capacitors (4) #6 Lock W ashers (1 Extra) (4) 820pF 500V Ceram ic Disc Capacitors (2) 27 ½W Resistors To start the installation, read these instructions very carefully. Now unplug the amplifier and remove any input, output and control cables that may be connected to the back of the am plifier. [. . . ] Slip the loop end of one of the parasitic choke/resistor assem blies over one of the plate cap screws with the coil up, followed by a #6 lock washer. Install this assembly on one of the plate caps with the assembly pointing toward the HV lug. Fish the free end of this assembly through the outer hole in the HV lug and trim the end to about 1/8". In a like manner, inst all the other parasitic choke/resistor assem bly onto the other plate cap, trimm ing the end to 1/8". Now solder the 3 wires going through the HV terminal of the plate choke. Turn the amplifier upside down with the front panel facing you. () () () () () () () () () () () 1 () Locate the (2) 1mH chokes going from the rear-most tube socket pin. In place of these chokes, install a 27 resistor paralleled with one 820pF disc capacitor (1 resistor/capacitor pair for each choke). On the right hand tube socket, parallel the existing 200pF capacitor closest to the front panel with (1) 820pF disc capacitor. On the left hand tube socket, parallel the 200pF capacitor on the extrem e left with the remaining 820pF disc capacitor. Locate the 2-lug terminal strip just behind the filament choke (the input drive coax is connected here). Clean solder from the terminal strip w here you just rem oved the capacitor. Install 1 lead of each of the 0. 01µF 1KV disc capacitors through the terminal you just cleaned. Have the body of the capacitors about 3/8" from the terminal with the c apac itors lying flat and pointing to the left. Take (1) 10 2W resistor and wrap a lead around the closest filament jumper connection (the one going between the tube sockets). [. . . ] Use the book to hold the am plifier while you reinstall the case and feet. . () () () () () () () () () () () () This completes the installation of the PS-220 Parasitic Suppressor kit. You will find that your amplifier tunes much m o re sm oothly than before and there will be no more arcing or spitting on voice peaks. HARBACH ELECTRONICS Jeff Weinberg ­ W8CQ 468 County Road 620 Polk, OH 44866-9711 (419) 945-2359 http://www. harbachelectronics. com info@harbachelectronics. com 2 [. . . ]